Ternary Plots in Python

How to make Ternary plots in Python with Plotly.

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Ternary Plots¶

A ternary plot depicts the ratios of three variables as positions in an equilateral triangle.

Ternary scatter plot with Plotly Express¶

Plotly Express is the easy-to-use, high-level interface to Plotly, which operates on a variety of types of data and produces easy-to-style figures.

Here we use px.scatter_ternary to visualize the three-way split between the three major candidates in a municipal election.

In [1]:

import plotly.express as px df = px.data.election() fig = px.scatter_ternary(df, a="Joly", b="Coderre", c="Bergeron") fig.show()

We can scale and color the markers to produce a ternary bubble chart.

In [2]:

import plotly.express as px df = px.data.election() fig = px.scatter_ternary(df, a="Joly", b="Coderre", c="Bergeron", hover_name="district", color="winner", size="total", size_max=15, color_discrete_map = {"Joly": "blue", "Bergeron": "green", "Coderre":"red"} ) fig.show()

Ternary scatter plot with Plotly Graph Objects¶

In [3]:

import plotly.graph_objects as go rawData = [ {'journalist':75,'developer':25,'designer':0,'label':'point 1'}, {'journalist':70,'developer':10,'designer':20,'label':'point 2'}, {'journalist':75,'developer':20,'designer':5,'label':'point 3'}, {'journalist':5,'developer':60,'designer':35,'label':'point 4'}, {'journalist':10,'developer':80,'designer':10,'label':'point 5'}, {'journalist':10,'developer':90,'designer':0,'label':'point 6'}, {'journalist':20,'developer':70,'designer':10,'label':'point 7'}, {'journalist':10,'developer':20,'designer':70,'label':'point 8'}, {'journalist':15,'developer':5,'designer':80,'label':'point 9'}, {'journalist':10,'developer':10,'designer':80,'label':'point 10'}, {'journalist':20,'developer':10,'designer':70,'label':'point 11'}, ]; def makeAxis(title, tickangle): return { 'title': {'text': title, 'font': { 'size': 20}}, 'tickangle': tickangle, 'tickfont': { 'size': 15 }, 'tickcolor': 'rgba(0,0,0,0)', 'ticklen': 5, 'showline': True, 'showgrid': True } fig = go.Figure(go.Scatterternary({ 'mode': 'markers', 'a': [i for i in map(lambda x: x['journalist'], rawData)], 'b': [i for i in map(lambda x: x['developer'], rawData)], 'c': [i for i in map(lambda x: x['designer'], rawData)], 'text': [i for i in map(lambda x: x['label'], rawData)], 'marker': { 'symbol': 100, 'color': '#DB7365', 'size': 14, 'line': { 'width': 2 } } })) fig.update_layout({ 'ternary': { 'sum': 100, 'aaxis': makeAxis('Journalist', 0), 'baxis': makeAxis('<br>Developer', 45), 'caxis': makeAxis('<br>Designer', -45) }, 'annotations': [{ 'showarrow': False, 'text': 'Simple Ternary Plot with Markers', 'x': 0.5, 'y': 1.3, 'font': { 'size': 15 } }] }) fig.show()

Reference¶

See function reference for px.(scatter_ternary) or https://plotly.com/python/reference/scatterternary/ for more information and chart attribute options!

What About Dash?¶

Dash is an open-source framework for building analytical applications, with no Javascript required, and it is tightly integrated with the Plotly graphing library.

Learn about how to install Dash at https://dash.plot.ly/installation.

Everywhere in this page that you see fig.show(), you can display the same figure in a Dash application by passing it to the figure argument of the Graph component from the built-in dash_core_components package like this:

import plotly.graph_objects as go # or plotly.express as px fig = go.Figure() # or any Plotly Express function e.g. px.bar(...) # fig.add_trace( ... ) # fig.update_layout( ... ) from dash import Dash, dcc, html app = Dash() app.layout = html.Div([ dcc.Graph(figure=fig) ]) app.run(debug=True, use_reloader=False) # Turn off reloader if inside Jupyter